Well one of the most disturbing things about the Genocide in Rwanda is that it wasn't a war. It was the indiscriminate butchering of man woman and child, for the crime of being born a Tutsi. Men had to kill their wives and children. One survivor of the marshes described how the priests, deacons, schoolmasters, and burgomasters wore their soft cotton pants, dress shirts, and rolled up their sleeves to get a better grip in their machetes.
Afterwards, the world wondered how they even knew who was a Tutsi, since they looked the same, intermarried, and shared a culture and language. The way the Hutus knew who was who, is because these Tutsis were their neighbors, friends, wives, children. These were the people they went to school with, The old woman that put medicinal plants on your wounds.
There's a lot more, you should read the book "machete season."